Spotrac has Detroit with around 30K in cap room, which is below the league average. Further, I don't have them cutting anyone notable. Marvin Jones is a cut candidate, but my thought is that he sticks around--hence why he's not on the notable cut list.
I go over this everytime I do a mock offseason: not every free agent is accounted for! I only included players (a) whose addition would affect how a team approached however many rounds I have mocked, or (b) whose subtraction would affect how a team approached however many rounds I have mocked.
Speedster receivers always tend to go higher than anticipated. When all is said and done, I think Brown will be viewed as a similar prospect as John Ross, who went around the same place in 2017.
The Dolphins aren't in a great spot cap wise even if they release/trade Tannehill. I figure James will command $8+ million a year in the open market which would be a tough pill to swallow for a rebuilding roster without a whole lot of cap space. I think Ingram signs for between $6-7 million--which is a lot more manageable.
Ajayi won't be signing for much this offseason. I'm thinking a 1-year deal at around $4-5 million. I think Ingram goes for around $1-3 million a year more.
Flacco will not be expensive if he's cut. I expect Flacco to sign at no more than $15 million per year. Also, I don't view the Giants as a total rebuild, just a rebuild at quarterback.
Lastly, expensive veterans still on the roster per this mock: Vernon, Beckham, Solder.

I'm surprised that Brees came up small down the stretch but I guess I shouldn't be--Brees wavering toward the end of games in the playoffs has been a major theme for him since his Super Bowl. Heck, I even remember him wavering in the Vikings-Saints Championship matchup his Super Bowl year--the refs saved him then and boned him now.

I entertained this thought when things were at their worst, but the team has plenty of cap space to keep both. Although they didn't play at an elite level last year, they, with Hudson, make for a very formidable interior offensive line which showed when the team ran between the tackles more often with Martin during the second half of the year.

True. Andy Reid is a create coach, schemer, and very good play caller. I would be hesitant to take anything away from Mahomes, though. It's clear to me after watching him play that he's an all-time talent.

Mahomes doesn't really run enough for me to worry about his play style.
To answer your second question: you're literally asking about a different player than Mahomes is. Are you asking what kind of player he'll become in 20 years? If so; lol why? And Mahomes is more than just arm strength and mobility. In fact, I'd say he's more arm strength and accuracy, which tends to age pretty well.
To answer your last question: why wouldn't he be?

Changing the subject: I watched Josh Jacobs after Daniel Jeremiah had him going top 5 and I've got to say that's around where I'd have him going, too. My comp for him is Ezekiel Elliot. In fact, I would be mad if the Raiders took him at 4--he's definitely on my list.

I think Mahomes more shows that not every QB has to look the same to be successful in the NFL. Mahomes, much like Rodgers, is simply a natural--not a whole lot of guys like him throwing the football.
Honestly, I don't know how much better or even if he'd be any better if his footwork and delivery looked like Brady.

He's Carr-ish in terms of how he'll play in the NFL. That said, I think he's an all-around worse version of Carr except for maybe his running ability. Carr has really become a pretty refined passer--especially this past year. I think a lot of Carr's success in the NFL has been due to his leadership ability, work ethic, and general grit and toughness--I'm not sure if Lock has those traits.
I think Drew Lock will and should go in the second round as Carr did, but I also think he's a comparatively worse prospect, too.

I'm pretty sure Graham returns to Philly. Za'Darius Smith probably hits the open market but I'm not convinced he'll be worth what his highest bidder will offer. A lot of his pressure and production comes from clever scheming and I don't see an overly strong or explosive player. A team is going to be disappointed if they decide to use him as a conventional edge rusher. That said, he's probably better than anything the Raiders currently have at end.
My preferred front 7 signings are still Preston Smith and Anthony Barr. I know what I'm getting with Preston Smith. He's an overall good end who is very good at setting the edge and he's an above average pass rusher. Barr is a player who I think was stifled by the scheme in Minnesota. Looking at the Miami game, Barr can rush the passer effectively and should rush the passer at least half the time he's on the field. It's a bit of a risk, but I like the upside in signing him to linebacker money but putting him to work effectively as an edge rusher.
Offensively, my priorities would be to go after Tyrell Williams and Bobby Massie. Williams is a quality overall receiver who can run every route, adjust to the ball, and has the ability to stretch the field. Massie adds assurance to the right sight of the offensive line as the presumptive starting going into the season. Hopefully, he also pushes Parker to get better and reach his supposed potential.

Myles Jack was the most ridiculous prospect I think I've ever watched. It seemed impossible that he would play as many snaps as he did and run as far and as hard as he did and not collapse by halftime. I mean, the man played man coverage against Nelson Agholor.